1. Field of the Invention
The present invention relates to capos, and more particularly to an improved capo which is adapted for providing maximum performance with respect to the musical instrument to which it is connected.
2. Description of the Prior Art
Capos are used in connection with stringed instruments, such as guitars, banjos, ukuleles and the like, which have a neck-like fretboard on which the strings are played. The capo is a clamp device which fits on the instrument neck and is used to selectively clamp upon the strings of the fretboard so as to alter the effective length of vibration of the strings. The purpose of the capo is to allow for selective alteration of the tonality of the strings without affecting the original tuning of the strings of the instrument. Thus, by placing the capo at a pre-selected location on the fretboard, a musican can play his/her instrument and produce a desired sound quality, since the pitch produced by the strings with the capo attached is different from the pitch produced by the stings with the capo absent.
In the prio art there are a number of capo structures. Each of these is basically a clamp type of device in which a bar is caused to press transversely across the strings by operation of an adjustable clamping mechanism that interacts with the underside of the fretboard. Examples of prior art capos are as follows.
U.S. Pat. No. 608,278 to Benson, dated Aug. 2, 1898, discloses a capo having a generally U-shaped main body, a bar connected to the upper portion of the main body for transversely contacting the fretboard strings, a foot for pressing against the underside of the fretboard, a screw operated clamping mechanism and a guide finger interconnected with the foot and the lower portion of the main body for keeping the foot from turning when the screw of the screw operated clamping mechanism is rotated to effect clamping of the bar onto the strings.
U.S. Pat. No. 656,904 to Pletcher, dated Aug. 28, 1900, discloses a capo having a bar for pressing transversely against the strings, a clasp member pivotally connected to the bar, an arm member connected to one end of the bar, and a spring steel clip pivotally connected with the arm and which is structured to selectively engage the clasp member.
U.S. Pat. No. 775,399 to Halladay, dated Nov. 22, 1904, discloses a capo having a bar for transversely engaging the strings, an arm connected to the bar, and a screw actuated lever clamp pivotally interconnected with the arm.
U.S. Pat. No. 1,007,960 to Moore, dated Nov. 7, 1911, discloses a capo having a bar for transversely contacting the strings, a rod pivotally connected at either side of the bar, and a screw operated foot pivotally connected to the free ends of the rods.
U.S. Pat. No. 4,104,947 to Oster, dated Aug. 8, 1978, discloses a capo having a U-shaped member of which the upper portion thereof serves as a bar for transversely engaging the strings, two off-set resilient string engaging members, a screw operated clamping mechanism connected with the lower portion of the U-shaped member and a foot interconnected with the clamping mechanism and a central portion of the U-shaped member.
U.S. Pat. No. 4,250,790 to Shubb et al, dated Feb. 17, 1981, discloses a capo having a bar with a resilient material for transversely contacting the strings, an arm connected to the bar, a curved jaw pivotally connected to the arm for contacting the underside of the fretboard, a lever pivotally connected to the arm in spaced relation with respect to the curved jaw, and a screw mechanism interconnected with the lever. Applicant believes this form of capo to be presently the most popular among musicians.
U.S. Pat. Des. No. 257,988 to Nakamoto, dated Jan. 20, 1981, discloses an ornamental design for a capo showing a yoke having a pivotally connected bar for transversely contacting the strings, a releasable clasp mechanism for holding the bar in fixed relation to the yoke, and a screw operated clamp mechanism which includes a foot for contacting the underside of the fretboard and guide rods for preventing the foot from rotating when the screw is rotated.
U.S. Pat. Des. No. 281,508 to McKinney, III, dated Nov. 26, 1988, discloses an ornamental design for a capo showing a yoke having a pivotally connected bar for transversely contacting the strings, a releasable clasp mechanism for holding the bar in fixed relation to the yoke, and a screw operated clamp mechanism which includes a foot for contacting the underside of the fretboard and a guide member for preventing the foot from rotating when the screw is rotated.
While each of the foregoing examples of capos accomplish their task in more-or-less acceptable fashion, there remains in the art the followin problems.
Each of the strings on the fretboard are of varying thickness, so that when the bar of the capo clamps down on the strings, the thicknest of the strings will be more pressably affected than the thinnest of the strings. While the use of a compressive material on the bar may allow for compressible engagement with the strings and thus to some degree mollify this problem (as pointed out particularly by Oster), there yet remains the problem that each of the strings is subjected to varying levels of compressive force, as prior art capos are structured to align the bar parallel with the surface of the fretboard.
Capos are of value because of the precision with which they may be placed upon the fretboard, which placement is predicated upon precise alignment of the component parts thereof. There remains in the prior art the problem that if the capo is subjected to accidental shock while being handled or transported, misalignment of the components could ensue.
So too, capos are of value because they are capable of being placed upon the strings in a true transverse orientation with respect thereto. In this regard, what is yet needed is a capo which has provision for guidance between the yoke and the foot which assures that play is absolutely minimized between the foot, the yoke and the bar, yet the operation of the foot and bar are fully unencumbered thereby.